1. Field of the Invention
The present invention relates to a recording medium and an image recording process using the recording medium.
2. Description of the Related Art
Recently, recording media having a texture, called luster surface or granular surface, (hereinafter, also referred to as “luster paper”) are highly demanded. The luster paper has fine roughness on the surface of the recording medium to appropriately suppress the gloss and to provide a high-grade texture.
Japanese Patent Laid-Open No. 2000-355160 discloses a recording medium having a surface of which arithmetic mean roughness in accordance with Japanese Industrial Standards (JIS) B 0601:2001 is 0.8 to 4.0 μm. Japanese Patent Laid-Open No. 2001-347748 discloses a recording medium having a surface of which arithmetic mean roughness in accordance with JIS B 0601:2001 is 0.4 to 2.5 μm. Both documents describe that the glare due to surface gloss of a recording medium is suppressed by roughening the surface as mentioned above.
A recording medium having a surface provided with purposely formed cracks has also been investigated. Japanese Patent Laid-Open No. 2002-166643 discloses glossy paper having a surface provided with cracks having a thickness of 3 μm or more and 15 μm or less and an area of 250 μm2 or more and 2500 μm2 or less. In such paper, even when a pigment ink is applied to the paper, the pigment particles penetrate into the cracks and do not remain on the surface of the recording medium, and the gloss of the image is therefore not reduced.
Investigations by the present inventors, however, demonstrate that images recorded on recording media having surface roughness as described in Japanese Patent Laid-Open Nos. 2000-355160 and 2001-347748 have metallic glossiness-like glare or cause bronzing in which reflected light alters the appearance of colors of coloring materials depending on viewing angle of the recorded matter. The recording medium described in Japanese Patent Laid-Open No. 2002-166643 does not have fine roughness on the surface and therefore cannot suppress glossiness and does not provide a luster surface. In addition, since the glossiness is high, bronzing occurs in some cases. Furthermore, since an ink easily penetrates into the recording medium, the resulting image may have an insufficient optical density.